Semiconductor devices, such as microprocessors, memory devices, and other integrated circuit (IC) devices, are subjected to rigorous electrical or "functional" testing in order to ensure proper operation over a specified range of possible operating conditions. One operating condition that is of particular concern is the operating temperature of the semiconductor device, and one type of testing, often called "temperature binning," requires performing a particular set of tests at each of a multiplicity of different operating temperatures For example, a semiconductor device might be tested at room temperature (ambient), at a specified minimum operating temperature (e.g., -50 degrees Celsius), and at a specified maximum operating temperature (e.g., 200 degrees Celsius). Devices are often sorted based on the results of the temperature binning tests.
According to typical prior techniques, temperature binning requires a device under test (DUT) to be cycled through the test system for each operating temperature tested, which is inefficient. For example, a typical test system includes a test head having a test socket for receiving a DUT, a handler for conveying the DUT through the test system, and one or more heating and/or cooling stations for heating or cooling the DUT to a specified temperature. For such a system, the handler inserts the DUT for testing at a first temperature, removes the DUT so that the DUT may be heated or cooled to a second temperature, and then reinserts the DUT for testing at the second temperature, repeating the process for each new test temperature.
The process of repeatedly inserting and removing a DUT from a test head so the DUT may be heated or cooled requires a considerable amount of time and therefore reduces the rate at which DUTs may be tested and sorted. It would be desirable to reduce test time by reducing the need to remove the DUT from a test head, once inserted